Pull off all the keychain stuff so you just have the little metal nub with the eye hole. String a bit of wire (a straightened paperclip or bobby pin works nice) through the eye hole and twist it off so it won't come out. Wrap the loose ends of the wire around something you can hang on to while you pull (I like to use a needle-nose pliers so that it can hold the ends so they don't unwrap themselves). Wrap the minifig in a towel or something to give you a better grip and pull the pliers and the minifig/towel as straight apart as you can. This is usually fairly hard; I find it easiest to set the pliers on the ground and stand on them while pulling the towel-fig straight up.

I've tried all the usual methods (like the one above) but either all my keychains are too stubborn or I'm just too weak, because I have yet to remove a single pin with brute force.

A few months back I came across the method listed here, about halfway down the page marked as #3 Using a Soldering Iron, and it's worked wonders every single time. There's really no effort required on your part, since the iron's heat does most of the work for you. I got mine from WalMart for about $8.

1. Plug the soldering iron into an electric outlet. Wait until it warms up (couple of minutes.

2. Align the loop on top of the minifig’s head in such a way that it has the most clearance. (You don’t want the soldering iron’s tip to touch and melt the plastic.

3. Carefully insert the heated tip into the loop on top of the minifig’s head.

4. Wait a couple of seconds as the soldering iron’s tip transfers the heat over to the pin in the minifig’s body.

5. The heat will gradually release the pin and you can easily pull it out. This should take no mare then 1-2 second. WARNING! If you don’t pull out the heating pin immediately, it will start melting the plastic, so don’t linger. Pull it out as soon as you feel the pin is being released. And you are done!

I used the wire pulling method on the Anubis guards and it took every ounce of strength I had to get the pins out and I'm a strong guy at 6' 3" 200lbs. It was genuinely physically challenging and exhausting ( I did 50 of them ).

On the other hand they came out of the Barracuda guardians easy as pie using the same method.

Thanks for the soldering iron tip. Seems like the thinking man's method, letting the tool do the work, I'm using that from now on.

I wanted to dechain a Flash minifig, and I didn't feel like digging through boxes to see where my hot iron (think soldering iron with interchangeable tips, including an X-Acto blade collet) ended up after two moves and over a decade. I popped the round link between the keychain and the post ring, and locked onto the post ring with some vise-grips. Bend it sideways to just snap it off. Remove the head, and do the same thing for the rest of the exposed stem, and you're good to go.